Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method and apparatus for transmitting system information for cellular internet-of-things (CIoT) in a wireless communication system.
Related Art
3rd generation partnership project (3GPP) long-term evolution (LTE) is a technology for enabling high-speed packet communications. Many schemes have been proposed for the LTE objective including those that aim to reduce user and provider costs, improve service quality, and expand and improve coverage and system capacity. The 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of a frequency band, a simple structure, an open interface, and adequate power consumption of a terminal as an upper-level requirement.
In the future versions of the LTE-A, it has been considered to configure low-cost/low-end (or, low-complexity) user equipments (UEs) focusing on the data communication, such as meter reading, water level measurement, use of security camera, vending machine inventory report, etc. For convenience, these UEs may be called machine type communication (MTC) UEs. Since MTC UEs have small amount of transmission data and have occasional uplink data transmission/downlink data reception, it is efficient to reduce the cost and battery consumption of the UE according to a low data rate. Specifically, the cost and battery consumption of the UE may be reduced by decreasing radio frequency (RF)/baseband complexity of the MTC UE significantly by making the operating frequency bandwidth of the MTC UE smaller.
Machine-to-machine (M2M) communication represents a significant growth opportunity for the 3GPP ecosystem. To support the so called “Internet-of-things” (IoT), 3GPP operators have to address usage scenarios with devices that are power efficient (with battery life of several years), can be reached in challenging coverage conditions, e.g. indoor and basements and, more importantly, are cheap enough so that they can be deployed on a mass scale and even be disposable.
Cellular IoT (CIoT) devices may require very low throughput, may not have stringent delay requirements like those required for real time services, may not need to support circuit switched services, may not need to support inter-radio access technology (RAT) mobility and may perform intra-RAT mobility by cell reselection. For CIoT, some additional features may be required.